The present invention relates to dimming and non-dimming electronic ballasts for powering fluorescent lamps. More particularly, the present invention relates to modular designs for various electronic ballast interface protocols making use of a common power motherboard.
Many different electronic ballasts are required to meet the diverse needs of the marketplace. A large fraction of ballasts are traditional fixed light output (non-dimming) ballasts. For these types of products, cost is a critical aspect of the design. Smaller, but fast-growing quantities of ballasts require various types of dimming capabilities. Ballasts have different operating characteristics depending on operating line voltage, types and quantity of lamps supported. Additionally, many different dimming interfaces and control systems exist
Certain ballasts have load shedding capabilities, where a remote signal may enable reduction of lighting energy consumption in response to peak or emergency grid events. A continuous dimming control protocol as known in the art, such as for example demand response protocols, provides optimal load management through AC power line-coupled control signals that may be received by the ballast for adjusting the lamp output accordingly. Demand Control Lighting (DCL®) is a proprietary example of such a ballast interface.
Ballasts may have automated continuous dimming capabilities where one or more ballasts connected in a loop receive digital control signals from a remote device capable of detecting for example ambient light conditions, and adjusting the lamp output levels in a manner known in the art as daylight harvesting.
Other ballasts as known in the art utilize digitally addressable interfaces, one example being DALI, an open industry standard protocol where various ballasts in a common loop may be individually controlled using device-specific addresses and digital control signals. AddressPro® is a proprietary example of such a ballast interface.
Still other ballasts as known in the art utilize phase control analog dimming, which provides a 1% to 100% dimming range using a phase control signal wire in combination with the hot and neutral AC mains line components, and/or various forms of an analog 0-10 VDC dimming range control signal. SuperDim® ballasts are a proprietary example of such a 0-10 Vdc protocol.
Present arrangements of these types of products require unique solutions such as printed circuit boards that are unique to each particular ballast and dimming protocol. Therefore, to meet market demands many different designs must be individually developed to support the varying needs. It would be desirable to provide a ballast design that could be separated into a dimming receiver and a power motherboard, such that many different ballast designs could rapidly be delivered by combining the common circuits. This would in turn enable lower development costs and more reliable final products.